Push rod structure and method of manufacture



Aug. 20, 1963 s. GONDEK 3,101,402

PUSH ROD STRUCTURE AND METHOD OF MANUFACTURE Original Filed Feb. 12, 1960 2 Sheets-Sheet l I V d 32 FIG. 2

Q Q 44 /I2 ,8 INVENTOR. l6 STANLEY GONDEK ATTOR N EYS Aug. 20, 1963 s. GONDEK PUSH ROD STRUCTURE AND METHOD OF MANUFACTURE Original Filed Feb. 12, 1960 7 2 Sheets-Sheet 2 Fla. 5*

'INVENTOR. STANLEY Gcwoe'K ATTORNEYS I for an electrodeto facilitate welding, which forms the seat for a coil spring inlthe valve train.

-ai 1d with another arm engaged with the push rod. Arm Z3-has a projection with 1 44'rea'cts against a retainer 46 not shown to engine block. 22

I aromas.

PUSH non sraucrona ANo Ernon F MANUFACTUREYL l.

. Stanley Gondek, Detroit, Mich, designer to Randy Tubing Company, Detroit,"Mich.',-a corporation of Michigan fi ibhtbz enemas Aug- -20,' ,1 cas portion of the tubular body surface, 52 is convex and is'provided by a conical pro- Original' application Feb. 12, 1960, Ser. No. 8,331, new I Patent No. 3,050,045, datedY Aug. '21, 1962. Divided andthis applicationFeb-28, 1961, Ser. No. 92,279

3 Claims; 219-107) part in a mechanical" train. Selectedlfor illustration of the'invention is a' push rod in the valvetrain of aninternal combustion engine.

A This application is a division of my co-pending application Serial No. '8,33l, filed February 12, 1960, now

Batent No. 3,050,045, and entitled Push Rod, Structure and Method of-Manufacture.

The object ofthe invention is to provide-alight weight;

{inexpensive push. rod structure of improved operating characteristics and a rapid, relatively inexpensive, im-

proved method of its manufacture. Generally the invention contemplates a tubular push rod body havingvsan end forming a seat to which a curved surface on an end pieceis welded. The end piece has a curvedfbearing surface disposed exteriorly of the tube and has a flange, one face of which One form of the invention is showninthe accompanying drawings.

. FIG. ,1 isa view partly in elevation and partly in section forms an abutment and the other face of illustrating a push rod according to this'inv'ention in use.

- FIG. 2 is an enlarged view of the push rod with portions broken away at one end to illustrate structure.

FIG. 3 is an enlargcd'perspective view of an end piece separate from the tube. 1

' FIG. 4 is a fragmentary partially sectional trating a step in manufacture of the push rod.

FIG; 5 is a view'similar to FIG. 4 illustrating a subsequent-step in manufacture of the push rod. Shown in FIG. 1' is .a 'pushrod 10 according to this View illusinvjention operably interconnecting a cup-shaped valve lifter 12 and a valve operating rocker 14. Lifter 12 is' raised and lowered by a cam 16 on a cam shaft-18 and he lifter moves in"- a guide 20formedin1 an engine block jection' 56. Flange 40 has a surface 58 which faces in a direction opposite from surface 42, and extending longi tudinally from surface 58 is a cylindrical projection 60 serving a purpose to be described. End piece 34 is preferably formed of a relatively hard material such as a case hardened steel and may conveniently be formed by cold forging. vBy this means exposed surface 36 provides a hardsznooth bearing surface for engagement with seat 3 8 on valve lifter. 12. Surface 36 is free of any'machining marks and requires minimal treatment subsequent to being forged and prior to use. End piece 34 is secured to an of tube 54 by'a fused metal connection such as by soldering, brazing or Welding.

hardened stamped part secured to the other end of tube 54 by a fused metal connection as disclosed in copendin-g application Serial No. 770,496, filed October 29, 1958,

Manufacture.

The tubular-push rod body 54 has open ends prior to Y the time when end pieces 32 and 34 are secured thereto. The tube manyhave any. cross sectional shape, although the round shape illustrated is suitable for most purposes and facilitates economicmanufacture. The tube may be of anysuitable rigid type, such as an extruded seamless tube or a rolled plural or single ply tube and may be made of any suitable material such as ferrous metal which will give it the requisite rigidity. An exampleof a suitable 'tubeis ya single ply rolled steel tube having a butt welded longitudin-al'seam.

In the form of the invention illustrated, 'endpiece 34 has been fastened to tube'54 by resistance welding. Conical surface 521's engaged against the seatfonned at an open end portion ofthe tube so that surface 52 and the seat engage in a generally annular region of contact. A

each other. End face 640 f electrode 62 engages face 58 Z 2. "Rocker 14 is rockably mounted on a shaft 24 with 5 ime arm 26 operably engagedwith a valve (not shown). 28 on the opposite side'of shaft 24 cup-shaped end piece 32 at one end of the push rod. i

The other end of the push is providedwith an end I piece 34 having a spherical end surface 36 bearing against a complementary spherical concave surface 38 in the bottom? of cup-shaped valve lifter 12. End piece .34 hasa 1 radialflange 40, one face 42 of which forms a seat for engagementtby an end of a coil spring 44 which is com pressed to bias bearing. surface I secured by suitable means ing 48 through which the push rod extends.

oneend a curved surface 52 which is secured to an end a ispherical surface 30 engaged within "a complementary a spherical concavity-in a 36 against seat .38. Spring.

and having a central open-j serving as a pilot I the axis of the end piece coincides substantially with the welding are illustrated at 66 and 68.

on flange 40 and urges conical surface 52 firmly against the end of tube'54; A welding current is then passed through end piece 3-4 and the tube to effect the welding.

During the Welding, the Walls defining the end of thetube are softened and end piece 34 and tube 54 movetoward each other to the general condition illustrated in FIG. 5.

During this process, the walls adjacent the end of the tube are flared somewhat in a radial the width of the weld and providing a very sturdy joint between the end piece and tube. Fillets formed during the In the form of the invention illustrated,-the various surfaces ofend piece 34 are substantially concentric around the longitudinal center line or axis of the end piece and longitudinal axis of tube Also in the structure illustrated, cylindrical portions and of the end piece have different axial di-mensions to facilitate hopper feeding'ofthe end piece to a electrode 62 and tube 54.

In use, spherical bearing surface36 is engaged spherical seat 3% on valve lifter 12 and spherical projection 30 on rocker V arm 23 is engaged within the comple mentary concavity in cup-shaped end piece 32. Since these interengaged surfaces are spherical, push rod 10 may have random rotative orientation about its longitudinal 54 of the rod in a manner to be described. In the form'of the invention illustrated,

Cup-shaped end piece iiz preferably comprises a case 0 direction, thus increasing position for engagement between I axis. The push rod generally in admirably adapted for interconnecting machine parts having rotary components of'motion such'las in the case 'of rocker arm- 28,

Flange 40 not onlyprovides a face 42 forming Iaseat for. vcoil spring 44 "but also provides a surface 58 for abutment by. electrode 62 during the weldingprocess. End piece 34 has "a ready-made bearing surface 36- obviating the necessity of expensive machining operations after its attachment to tube 54. The invention facilitatesv inexpensive manufacture since the tubing and end piece 34 are relatively" inexpensive and since the open end of the tube provides a seat for engagement with end 'piece 34- so a that special machining or other preparation of the tube is minimized or obviated in providing the seat. The invention provides a push rod which is formed of a hollow tube and which is relatively light weight so that the efficiency of an engine or machine in which the push rod is used will be increased. a

' 1. The method of forming a push rod having a flange adjacent one end to provide a seat for a coil spring which comprises, providing a tube having an end portion forming a seat, providing an element having portions lying 1 generally on a cylindrical surface and extending between a bearing surface at one end of the element and a fixed flange, one face of said flange forming said spring seat against said tube seat and while leaving said bearing surface free of contact with said hollow electrode and while continuing to use said hollow electrode as an aligning holder for said element, forcibly engaging said end face of said hollow electrode substantial-1y axially against said pressure seat on said flange and thereby applying longitudinal force urging said curved surface against said tube seat, and while continuing to supply said force, heating the interengaged seat and curved surface to form a fused:

metal connection therebetween. I

2. The method defined in claim 1 and including in addition the steps of providing said curved surface with a generally conical conformationdimensioned to enter at least partially within said tube seat and utilizing the interengagement of said conical conformation and tube seat to assist in aligning said tube seat and element in substantially co-axial relation. 3 t i .t

3. The method "of providing a bearing surface and a seat for a coil spring on one end of a push rod having an open tubular end forming said seat comprising, providing a blank, performing Work on's aid blank to provide an element having portions lying generally on .a cylindrical sur-' face extending between a bearing surface'at one endtof the element and an integral flange, saidflange having' one face which forms said spring seat and an opposite face forming a pressure seat, said element having a curved surface adjacent the end opposite said bearing surface, providing a hollow electrode having an end face, engaging said'hollow electrode abound said portions of said element while leaving said bearing surface free of contact with said electrode, aligning said hollow'electrode substantially coaxially with the tube seat, utilizing said'hollow electrode as a holder for said element and thereby aligning said element substantially co -axially with said :tube seat, engaging said curved surface against said tube seat and While vleaving said bearing surface free of contact with said,

hollow electrode and while continuing to use said hollow electrode as an aligning holder for said element, forcibly engaging said end face of said hollow electrodesubstantially axially against said pressure seat on said flange and thereby applying longitudinal force urging said curved surface against said tube seat, and while continuing to apply said force, heating the interengaged seat and curved surface to form a fused metal connection therebetweenl.

References Citedin the file of this patent;

V UNITED STATES PATENTS 

1. THE METHOD OF FORMING A PUSH ROD HAVING A FLANGE ADJACENT ONE END TO PROVIDE A SEAT FOR A COIL SPRING WHICH COMPRISES, PROVIDING A TUBE HAVING AN END PORTION FORMING A SEAT, PROVIDING AN ELEMENT HAVING PORTIONS LYING GENERALLY ON A CYLINDRICAL SURFACE AND EXTENDING BETWEEN A BEARING SURFACE AT ONE END OF THE ELEMENT AND A FIXED FLANGE, ONE FACE OF SAID FLANGE FORMING SAID SPRING SEAT AND THE OPPOSITE FACE THEREOF FORMING A PRESSURE SEAT, SAID ELEMENT HAVING A CURVED SURFACE ADJACENT THE END OPPOSITE SAID BEARING SURFACE, PROVIDING A HOLLOW ELECTRODE HAVING AN END FACE, ENGAGING SAID HOLLOW ELECTRODE AROUND SAID PORTIONS OF SAID ELEMENT WHILE LEAVING SAID BEARING SURFACE FREE OF CONTACT WITH SAID ELECTRODE, ALIGNING SAID HOLLOW ELECTRODE SUBSTANTIALLY CO-AXIALLY WITH THE TUBE SEAT, UTILIZING SAID HOLLOW ELECTRODE AS A HOLDER FOR SAID ELEMENT AND THEREBY ALIGNING SAID ELEMENT SUBSTANTIALLY CO-AXIALLY WITH SAID TUBE SEAT, ENGAGING SAID CURVED SURFACE AGAINST SAID TUBE SEAT AND WHILE LEAVING SAID BEARING SURFACE FREE OF CONTACT WITH SAID HOLLOW ELECTRODE AND WHILE CONTINUING TO USE SAID HOLLOW ELECTRODE AS AN ALIGNING HOLDER FOR SAID ELEMENT, FORCIBLY ENGAGING SAID END FACE OF SAID HOLLOW ELECTRODE SUBSTANTIALLY AXIALLY AGAINST SAID PRESSURE SEAT ON SAID FLANGE AND THEREBY APPLYING LONGITUDINAL FORCE URGING SAID CURVED SURFACE AGAINST SAID TUBE SEAT, AND WHILE CONTINUING TO SUPPLY SAID FORCE, HEATING THE INTERENGAGED SEAT AND CURVED SURFACE TO FORM A FUSED METAL CONNECTION THEREBETWEEN. 